Planer attachment for planing curved surfaces



NITED STATES GRIFFITHS M. GRIFFITHS, OF ALTOONA, PENNSYLVANIA.

PLANER ATTACHMENTFOR PLANING CURVED SURFACES.

SPECIFICATION forming part of Letters Patent No 390,29 dated October 2,1888.

Application filed August 31, 1887. Serial No. 2 19.358. (No model.)

To aZZ LlJhOfit it may concern.-

Beit known that I, GRIFFITHS M. GRIFFITHS, a citizen of the UnitedStates, and a resident of Altoona, Pennsylvania, have invented certainnew and useful Improvements in Machines for Planing Curved Surfaces, ofwhich the following is a full, clear, and exact description, referencebeing had to the annexed drawings, making part hereof.

Heretofore after the cast of a device having a curved surface wasmade-for instance, a smoke-box saddle of a locomotiveithas beencustomary to finish and true it by means of cold-ehiseling. This methodof finishing is slow and laborious, and depends entirely upon the eyeand judgment of the workman for its accuracy. The object of my device isto accomplish the work wit-h nnerring accuracy and uniformity and in anexpeditious manner.

The nature of my invention will be apparent from the followingspecification and claims.

In the drawings, Figure l is a partial front view or elevation of adoubleheaded planinginaehine with my device attached thereto,onl y onehead of the machine being shown; Fig. 2, a small detached perspectiveview of the templet for the tool-holder.

The general construction of the planing-machine is that in ordinary use,well known to mechanics, and will therefore require no specialdescription.

A is the frame of the machine; B, the bed upon which the platen ortraversingtalole 0 moves in guides backward and forward,npon which tablethe device to be planed is locked or set; D, the cross-frame whichcarries the laterally-moving heads F G and right-and-leftscrew-threadedrods E E, which by their revolution impart motion to the heads to changethe lines of cut of the tools. The plate F of the head shown is gearedin its rear to screwthreaded rod E in the ordinary way, and by thelatter is made to shift its line of out. The plate G slides verticallyupon the round plate F, which latter is pivoted so that it can be movedwhen angular sides are to be planed.

His the ordinary hinged flap or apron which carries the tool.

I is a downwardlyprojecting pin, shoulder, or lug, with rounded endattached to the lower part of the vertically-moving plate G.

I is the tool provided. with a rounded cutting end, which tool is alwaysrigged or set in line with the pin I.

J is a curved teinplet. This guide is a flanged edge of the plate J,which latter is stationary, and is attached to the crossframe D by boltsP P. (See Fig. 2.) The templet is so curved as to guide the tool to makean even out throughout upon the curved surface being planed. This isillustrated in Fig. 1 of the drawings, where the curve of the templet isthe same as that of the surface to be planed; but the circle of which itis an arcis described from a center slightly above that of the are ofthe curved surface to be planed, whereby the two arcs would intersect ifcarried out.

K is the half of the saddle to be planed. This saddle and the cylinder Mare cast in one piece, but the latter has nothing to do with myinvention.

L designates the curved surface of the saddle to be planed.

N N N are mere supporting-blocks for the mass of casting.

O is the cranlohandle of the vertical screw, which, engaging with afemale serewthread on the back of plate G, lowers the latter so as torest the pin I upon the templet J.

R is a rod provided with a spline or feather which passes through thehubof a beveled gearwheel behind plate G. This beveled gear-wheel engageswith a beveled gear-wheel upon the vertical screwthreaded rod, of which0 is the handle, and when rod R is turned by a crank or wheel from oneof its ends it turns the screwthreaded rods by means of their gears andthus lowers or raises the plate G. Thus this plate can be raised orlowered by the operative by means of handle 0 or rod It; but these devices are old and well known and require no further description.

The cross-frame D forms part of the frame of the machine.

The operation is as follows: The cut begins at the point lettered S andterminates at that lettered T. Thus, looking at the drawings, thetraverse of the plate F on the screwthreaded rod E is from left toright. The plate G- is kept depressed by the operative, so as to holdthelower edge of the round-ended pin I down upon the templet J. Afterthe carryingplate 0 has carried the saddle under the tool I for thewhole length of the saddle the plate 0 is returned'to the starting-pointand the tool is automatically shifted to the right for the next line ofcut, in the usual way. This operation is repeated, the operative keepingthe pin I down to its place on the templet J until the whole width ofthecurved surface is planed. If it is found that one traverse of the Wholecurved surface is not sufficient, the operation can be repeated untilsufficient metal has been removed to suit all requirements.

As stated above, I have not entered into a full description of the mainworking parts of the planer, because they are old and wellknown. Mytemplet and the pin or shoulder I, which rests upon it, can be removedat will, and the machine can be used for ordinary planing purposes.

The plate G has sufficient vertical play for planing any ordinary curvedsurface; but if a particularly-curved line of work is required to beperformed a special head will have to be constructed to enable thecutting-tool I to reach to the greatest depth of the curve.

The tool in my device strikes the object to be planed in a verticalline, and if the arc of the curve of the templet J were concentric withthat of the curved surface to be cut it will be apparent that the pointof pin Iwould gradually approach closer to the surface to be cut as itprogressed from point S to point T,

thus deepening the cut as the head traversed to the right. For thisreason the curved line of the templet is so directed as gradually towiden the space toward the right between it and the curve of the surfaceto be planed. The two curves are differential, thus keeping thevertically-acting pin I at a uniform distance from the surface L for thewhole width of the said surface and restraining the rigidly set tool Ifrom making an uneven cut. The whole surface is thus planed evenly.

If the plate G were pivoted to or swung from the center from which thearc of curve L may be described and were held rigidly for each cut,beginning at point S, and then swung to the right for each successivecut, the arc of the templet could be made concentric with that of thecurved surface to be planed.

It is evident that the pin I may form an integral part of plate G if thehead is designed for use in planing curved surfaces only. It is screwedinto the lower part of plate G in my device.

My invention relates, of course, to metalplaning machines.

\Vhile the tool is directly attached to apron H, this apron and plate Gmay be said to constitute the tool'carrying parts of the machine.

It will be observed that although I plane a curved surface mycutting-tool makes a regular and straight cutin the ordinary way. By soshaping the guide I can raise and lower the tool as it traverseslaterally across the object being cut, so as to adapt my machine to soplane any object that its surfacein transverse section will conform tothe shape of the guide.

What I claim as new is- 1. In combination with a planing-machine, thecurved templet J, supported from the frame of the machine, the pin I,attached to the vertically-movable tool-carrying part of the machine andresting upon the templet, whereby a curved surface may be developed bythe cuttingtool, substantially as described.

2. In combination with aplaning-machine, the templet J, supported fromthe frame of the machine, the pin or shoulder I, attached to thevertically-movable tool-carrying part of the machine and restingupon-the templet,

and the round-nosed cutting-tool I, substantially as and for thepurposes described.

3. In combination with a planing-machine, the detachable templet J,supported from the frame of the machine, the pin or shoulder I, attachedto the vertically-movable tool-carry ing part of the machine and restingon the curved templet, whereby a curved surface may be developed by thecutting-tool, substantially as described.

In witness that the above is my invention I have hereunto set my hand.

GRIFFITHS M. GRIFFITHS.

\Vitnesses:

GEORGE E. BUCKLEY, H. V. BUcKLEY.

